The primary ingredient in a traditional Japanese sushi roll is rice, specifically sushi rice, known as "shari" or "sumeshi." This short-grain rice is seasoned with a mixture of rice vinegar, sugar, and salt, giving it a unique flavor and sticky texture that is essential for holding the sushi together. Sushi rolls, or "makizushi," typically contain various fillings, such as fish, vegetables, or seafood, and are often wrapped in seaweed known as nori. The art of sushi-making emphasizes freshness and presentation, and it has evolved into many styles and varieties, reflecting regional ingredients and culinary traditions within Japanese cuisine.